Learn Hardcore Croatian: Za mene je Ana najbolja učiteljica.

Because the preposition za (“for”) always takes the accusative case. The accusative of ja (“I”) is mene (stressed form). After prepositions you use the stressed form, so:

Nominative: ja
Accusative: me/mene (after a preposition: almost always mene) So, standard Croatian says za mene, not “za ja.”

Could I say “za me” instead of “za mene”?

Not in normal, modern speech. Za me is archaic/poetic. In standard contemporary usage, say za mene.

What’s the difference between “za mene,” “po meni,” and “meni/mi” at the start of the sentence?

They all introduce a personal stance but with different nuances:

Za mene = “for me / as far as I’m concerned,” often implies a personal perspective or suitability (“for my needs/taste”). Common and neutral.
Po meni = “in my opinion.” Very common in speech; a straightforward “this is my opinion.”
Meni je … / … mi je … (dative) = “to me, … is …,” often feels the most personal/affective (“I personally find/feel that…”). Extremely common in everyday talk. All three work here; choose by nuance and style.

Why is the verb “je” placed after “Za mene” and before “Ana”?

Je (3rd-person singular of “biti” = “to be”) is an enclitic and follows the “second position” rule: it must come right after the first syntactic unit in the clause. Here, the first unit is Za mene, so we get:

Za mene | je | Ana … If you start with “Ana,” it becomes:
Ana | je | …

Can I change the word order, and does it change the meaning?

Yes, word order is flexible, and differences are mostly about emphasis:

Za mene je Ana najbolja učiteljica. (Fronts your viewpoint.)
Ana je za mene najbolja učiteljica. (Fronts Ana; “for me” is backgrounded.)
Ana je najbolja učiteljica za mene. (Puts “for me” at the end for afterthought/emphasis.) All are correct as long as je stays in second position relative to the first unit.

Can I omit “je”?

No in a full sentence; Croatian requires the copula in the present. You can omit it only in headlines, notes, or appositions (e.g., “Ana — najbolja učiteljica”), or use to-sentences (“To je Ana, najbolja učiteljica”), but the standard full clause needs je. For emphasis, a rare full form jest exists: “Ana jest najbolja učiteljica” (indeed she is).

How do I negate the sentence?

Use nije (ne + je → nije):

Za mene Ana nije najbolja učiteljica. Placement still respects the second-position behavior of the clitic form: “nije” sits after the first unit (here, “Za mene” or “Ana,” depending on your word order).

Why is it “najbolja,” not “najbolji”?

Agreement. Najbolji is the masculine form; najbolja is feminine singular nominative, agreeing with učiteljica (a feminine noun referring to a female teacher). If it were masculine (učitelj), you’d say najbolji učitelj.

What exactly is “najbolja” grammatically?

It’s the superlative form of the adjective dobar (good):

good: dobar/dobra/dobro
better: bolji/bolja/bolje (comparative)
best: najbolji/najbolja/najbolje (superlative) Here we need the feminine form najbolja to match učiteljica.

Why is “učiteljica” in the nominative case after “je”? In some Slavic languages I’ve seen an instrumental there.

In Croatian, the complement of the copula biti (“to be”) is normally in the nominative: Ana je (najbolja) učiteljica. Instrumental can appear with verbs of becoming, calling, considering, etc. (e.g., “Postala je učiteljicom” = “She became a teacher”), but with a simple “is,” nominative is standard.

Could I use “učitelj” instead of “učiteljica”?

Only if the teacher is male. Croatian typically uses gendered nouns:

male teacher: učitelj → “najbolji učitelj”
female teacher: učiteljica → “najbolja učiteljica” Depending on the school level, you may also hear nastavnica (subject teacher, usually middle/high school) or profesorica (especially high school/university).

Is any comma needed after “Za mene”?

No comma is required. You’ll often see no comma after short fronted adverbials like Za mene. A comma can be used for special rhetorical pause, but it’s not standardly needed here.

What’s the difference between “Ana je najbolja učiteljica” and “Ana je moja najbolja učiteljica”?

Ana je najbolja učiteljica. = She’s the best teacher (in general), with no explicit reference to you.
Ana je moja najbolja učiteljica. = She’s my best teacher (among the teachers you personally have/had). The moja ties it to your own set.

Can “za mene” mean “for my needs/for me personally (as my teacher)” rather than a general opinion?

Yes. Za mene can imply either “in my opinion” or “for me personally/for my needs.” In this sentence, context decides: it can mean “as far as I’m concerned (opinion), she’s the best” or “for me personally (as my teacher), she’s the best.”

Is “Ana” in the correct case here? Why not “Anu”?

Yes, Ana is nominative because she’s the subject. Anu is accusative and would be used if Ana were a direct object (e.g., “Vidim Anu” = “I see Ana”). Here, Ana is the one being identified as the best teacher, so nominative is required.

How would I pronounce the tricky letters in “učiteljica”?

č is like English “ch” in “church.”
lj represents a palatal “l,” similar to the “lli” in “million” said smoothly. A rough syllable guide: u-či-tel-ji-ca.